Abstract
Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispersed Au-1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH4+ Faradaic efficiency of 11.1% achieved by our Au-1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH4+ yield rate of 1,305 mu g h(-1) mg(Au)(1) has been reached, which is roughly 22.5 times as high as that by supported Au nanoparticles. We also demonstrate that by employing our Au-1 catalyst, NH4+ can be electro-chemically produced directly from N-2 and H-2 with an energy utilization rate of 4.02 mmol kJ(-1). Our study provides a possibility of replacing the Haber-Bosch process with environmentally benign and energy-efficient electrochemical strategies. (C) 2018 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.